Anatomy & Physiology
A practical map of the body's structures and systems
Lesson 5 of 20
The four primary tissues
A tissue is a group of cells and their surrounding material organized for a shared function. The four primary categories are epithelial, connective, muscle, and nervous tissue. Organs combine several tissue types, so a structure rarely performs its role through one tissue alone. Understanding these categories clarifies what massage can and cannot directly affect.
Key points
- Epithelium covers surfaces, lines passages, and forms many glands.
- Connective tissue supports, binds, protects, stores, and transports.
- Muscle tissue generates force through contraction; skeletal muscle is generally voluntary.
- Nervous tissue detects stimuli and communicates through electrical and chemical signals.
- Blood, cartilage, bone, adipose, and tendons are connective tissues with distinct properties.
Key terms
- Epithelium
- Tissue that covers, lines, and forms glandular surfaces.
- Connective tissue
- Tissue that supports and connects structures, with cells in an extracellular matrix.
- Muscle tissue
- Contractile tissue that generates tension and movement.
- Nervous tissue
- Tissue specialized to receive and transmit information.
- Extracellular matrix
- Material outside cells that influences connective tissue strength and behavior.
Memory tip
E-C-M-N: covering, connecting, moving, communicating.
Clinical note
Massage pressure is adapted to tissue tolerance; tissues are not interchangeable targets.
Unit checkpoint
Lock it in: match the terms, then test yourself.